Attribute multiple-choice in Brevo will break the available custom fields list

Problem/Motivation

If you define an attribute of type multiple-choice, the custom fields list (/admin/config/services/sendinblue-api/fields) will be empty.

This is due to a bug in the SDK already reported https://github.com/getbrevo/brevo-php/issues/40

Proposed resolution

Use the attached patch in your composer.json:

        "patches": {
            "getbrevo/brevo-php": { 
                "[issues/40] Support for multiple-choice attribute --- avoid breaking sendinblue_api custom fields list": "patches/getbrevo_brevo-php/brevo-php_multiple-choice-support_40.patch"
            }
        },
        "enable-patching": "true",